Convergence is in the air again, but this time the focus is not on multi-media phones or bizarre combinations of functions like pacemakers with integrated MP3 players and DAB radios.

The real interest at the moment is convergence at the service delivery end, following NTL's purchase of Virgin Mobile last week and Sky's earlier acquisition of internet service provider Easynet.

Virgin TV, as the combined NTL/Virgin business is likely to be branded later this year, will be the first combined communications company in the UK to offer cable TV, broadband, and both fixed-line and mobile telephone services to its customers.

Most people call this "quadplay", though Virgin's Richard Branson prefers the seaside postcard-level double entendre of "fourplay", and it is being pushed as the next big thing for communications companies, whether they started off in telephony or television.

BT is already planning to offer Freeview TV over its network, while Sky is trying to decide how best to use its recently acquired internet capability.

And it is not just a UK trend.

In Canada, cable company Rogers Communications is working towards the same goal, and US mobile operator Sprint already provides mobile phone services to customers of the main cable network companies there.

Support lines

The move towards a single company offering a wide range of communications services is clearly driving a lot of deal-making around the world, but we need to be careful before we announce that vertically integrated service delivery is the future.

Perhaps the real innovation will come from companies that know how to shift all sorts of data around the network, like Google, rather than those who know how to do only voice or moving pictures

After all, Virgin does not actually own a phone network but buys capacity from T-Mobile in the UK.

NTL is not buying a network but a brand and a customer billing relationship. The network is still run by a different company, whatever it says on the bill.

Still, perhaps Virgin Mobile will be able to do something about the level of customer service provided by NTL, especially for their broadband customers like me.

I've been fortunate enough never to need them for detailed technical advice, but those of my friends and family who have tried to resolve problems with the help of their phone support lines have found it consistently painful.

Recently they have started charging for the service, adding invoice to injury.

Loss leader

In terms of strategy the merged NTL/Virgin seems to have some interesting ideas, including not charging customers for television services if they use all three of their telecoms offerings.

This is deeply ironic for anyone like me who remembers the Cable Authority set up in 1985 by Margaret Thatcher's government to sell franchises for cable television service across the UK.

Richard Branson built up the Virgin Mobile brand

Cable TV was to be the next big thing, competing with satellite and terrestrial services to turn the UK television industry into an economic giant.

It didn't quite work out that way, as NTL and Telewest, the recently merged once-bankrupt remnants of that early optimism, can testify. Now cable is going to be the loss leader, the marketing equivalent of cheap cans of baked beans in a supermarket.

One reason why Virgin TV is considering giving away its television service may simply be a recognition that the sort of market likely to be attracted to the Virgin brand is younger and more likely to see TV as a nice extra than NTL's established customer base.

Another may be a desire to distinguish itself clearly from Sky. Virgin will be a telecoms company that does TV, while Sky is always first and foremost about television. Giving away cable TV is a subtle way of undermining the value of what Sky has to offer.

But whatever their motives, it reveals something about the future of television as a special service delivered using specific communications protocols over dedicated networks to standalone screens.

It reveals that this model is breaking down and no longer sustainable. In the near future, the word television will just be shorthand for watching something fullscreen on whatever display device is nearest to hand.

Data flows

Back in October 1994, sci-fi writer Neal Stephenson described a network dystopia in which all of the world's data came down one big fat connection he called the Spew.

The current round of mergers, collaborations and deals is taking us to the world of the spew, although we're not there yet.

And we can't be sure which of today's companies will thrive or even survive in the bit-oriented world we are building on top of the internet protocols and network standards we've developed over the past 30 years.

After all, just as NTL and Virgin were announcing their tie-up over here, the city of San Francisco revealed that the contract to provide a free municipal wi-fi service has been given to a consortium of Google and Earthlink.

Perhaps the real innovation will come from companies that know how to shift all sorts of data around the network, like Google, rather than those who know how to do only voice or moving pictures.

Bill Thompson is a regular commentator on the BBC World Service programme Go Digital